Telephone system



W. WHITNEY TELEPHONE SYSTEM March 10, 1931.

Filed Aug. 9, 1929 9 Sheets-Sheet l INH lgf" e lfHh N W WHITNEY BY F752 Haz/0 A TTURNEY l w. .WHITNEY March l0, 1931.

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TELEPHONE SYSTEM l Filed Aug. 9. 1929 I 9 Sheets-Sheet 4 W. WHITNEY 5)/ A fram/Ev 'March 1o, 1931. w. WHITNEY 1,795,813

TELEPHONE SYSTEM lFiled Aug- 9, 1929 9 Sheets-Sheet 5 /Nl/E/vrof? W WH /TNEY A TTRNEY March l0, 1931. w. WHITNEY TELEPHONE SYSTEM Filed Aug 9, 1929 9 Sheets-Sheet 6 LII NW .WH www w.

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' TELEPHONE SYSTEM Filed Aug. 9, 1929 9 Sheets-Sheet 9 Patented Mar. 10, 1931 e cire STATES PATENT orties wiLEY WHITNEY, OE EAsfr ORANGE, NEW VJERSEY, AssIGNOE To BELL TELEPHONE' A LABORATORIES, INCORPORATED, E NEW YORK, N. Y., A OOEPOEATIONOF NEW 1 TELEPHONE SYSTEM Application inea August 9, 1929. serial No. 384,619.

This invention relates to telephone systems and particularly to signaling arrangements in'trunking systems.

In trunking systems where it is the prac-l tice for the originating operator to select an idle outgoing trunk at randoni,'the connection ofthe incoming` operators set tofthe seized trunk is made known to the originating of a signal comparable in function tothe order tone. As a specific `eXainpleQthere are what are known as call announcer trunks wherein apparatus at tlie Outgoing end upon receipt of the signal comparable to the Order tone7 will mechanically pronounce the information necessary tobe imparted to the incoming operator in such a manner that she will hear the spoken words.

For purposes of designation therefore the y 'Figs Itand 5 illustrate the Operators control` term corder signal will be used herein vto y cover both the order tone7 which is trans- Vmitted to the ears of the outgoing operators' and the signal which 'is transmitted to the apparatus of suchmechanism as that of the call announcer trunks.

Due to the complexity rof the telephone systems in great metropolitan centers it is necessary that difverent types of order signals be `used to transmit proper information in accordance with the type of trunk being used l at any given time. For instance it is necesin one Acase to import the information i that only the name of the office to which the call being handled is' directed is to be pro nounced; in another case that both the name of the office and the number of the wanted line is to be pronounced; and ina third case that only the number of the wanted line is to be pronounced. In order to secure a standard method of operation, therefore, there must be means for giving an Order signal which is distinctive for each such v'class of seryice'and usually such means is incorpo-v vrated in what is known as the operators control circuit whichunder the proper conditions operates toconnect the incoming operators set to a seized trunk.

Due also to the complexity of the telephone' systems in great metropolitan centers where incoming trunks from al large number of other points have to be served at one point, it is necessary that an incoming operatorr be able to handle traffic over morethan one type The'drawingsconsist of nine sheets of cirenA cuit diagrams and arranged according to 10 andFg. 11, illustrating two formgofth present invention. A

Fig. l shows a call lannouncer trunk and its l associated sequence circuit;

Fig: 2l shows a straightforward trunk and its associated sequence circuit; f

Fig. 3` illustrates a splitting circuitand and telephone'circuit suitable for cooperating with the' particular arrangements Aofthe trunks shown in lFigs. 1 andQ; j i' i F ig. 6 showsl a straightforward tandem trunkv `and its associated sequence` circuit similar to that shown in, Fig. 2;

Fig. 7 shows a call announcer trunk and its associated sequence circuit similarjto that shown in Fig. l; i f

Figs. 8 and 9 illustrate the operators control and telephone circuit suitable for cooperj ation with the particular arrangements of trunks shown in Figsl, 6 and 7.

In general the arrangement shown vin the drawings, in accordance with Fig. 10, is such that the Operators control circuit automati-'f` cally differentiates between incoming. trunks through the connections of the tip and ring` conductors from-the sequence circuit to the splitting circuit. If a call comes in over the straightforward trunk of Fig. 2, then due tothe fact that the tip and ring4 conductors n arel connected straight through from the sei quence circuit, the operators control circuit will return an order signal in the form ot two momentary applications of order tone. lt' on the other hand a call comes in over the call announcer trunk of F ig. 1, then due to the fact that the tip and ring conductors are reversed. between the sequence circuit and the splitting circuit, the operators control circuit will return an order signal in the ormot a direct current which will cause a battery reversal over the trunk.

In the arrangement shown in Fig. 11, when a call comes in over the straightforward trunk of Fig. 2, then due to the i'act that the tip and ring conductors are connected straight through from the sequence circuit to the splitting circuit, the operators control circuit will return an order signal in the form oil2 two momentary applications ot order tone both of the same pitch. l/Vhen a call comes in over the straightforward tandem trunk ot Fig. 6, then due to the fact that the ring conductor is blocked by a condenser between tue sequence circuit and the splitting circuit, the operators control circuit will return an order signal in the orm or" several successive inomentary applications of order tone or" different pitch. Vhen a call comes in over the call announcer trunk of Fig. 7, then due to the tact that the tip conductor is blocked by a condenser between the sequence circuit and the splitting circuit, the operators control circuit will return an order signal in the form ot a direct current which will cause a battery reversal over the trunk conductors.

A splitting circuit shown in Fig. 3 is that part ofthe total circuit used for a whole team ofoperators pertaining` to a single position. It will be noted that whilethis circuit serves three se uence circuits this is merel repre-` the trunks served by both the middle sequence circuit and the indicated right hand sequence circuit will be handled by the operator to the right. It the lett hand group of relays ot the splitting circuit is operated, then the trunks served by other sequence circuits to the le'ft are cut off from the position here indicated. lWhen each of the operators has operated the left hand group or splitting relays, then each operator may confine her activities to the trunks normally appearing at her own position. Thus a flexible operating arrangement is provided so that with 'an operators control and telephone circuit like that of Figs. l and 5 or like that ot Figs. 8 and 9, the objects oi the present invention may be realized even in the case where all the trunks at one position are of the same nature, but differ Jfrom those of adjacent positions.

`When the straightforward trunk at Fig. 2 is seized at its outgoing end, battery and ground are placed on the conductors 200 and 201, whereupon current will flow through the two windings of relay 202 in series. Relay 202 becoming energized, places ground on conductor 203, which will extend through the inner, upper armature and back contact of relay 20e, the upper winding of relay 205 to battery and ground. Relay 205 becomes operated and completes a. connection from the ground on conductor 203 through the lower winding of relay 205, the back contact and lower armature of relay 206, conductor 207, iront contact and inner lower armature of relay 205, lower winding of relay 205, lower winding of relay 20% to battery and ground. Relay 204i becomes operated in this circuitin series with the lower winding of relay 205,7which now holds through such lower winding. Upon the operation ot relay 204, a circuit to* signal lamp 208 is established from battery, lamp 208, conductor 209, outer upper armature and front contact of relay 20e, upper armature and front Contact of relay resistance 210 to ground.

Bue to the operation of relay 205 a circuit is now established from ground, lower arma ture and front contact of relay 205, conductor 211, winding' otl relay 212, conductor 213, conductor 300, lower armature and back contact o'frelafy 301, conductor 802, conductor 21e', conductor 100, back contact and lower armature of relay 101, conductor 102, through the back contacts and lower armatures of other relays of the sequence circuit similar to relay 101, back contact and lower armature or" relay 103, conductor 104i, conductor 215, conductor 303, lower armature and back Contact or relay 304, conductor 305, through the chain circuit of the next indicated sequence circuit, conductor 300 to battery. Relay 212 becomes energized in this circuit and through its inner upper armature connects the winding of relay 210 to conductor 217. Conductor 21T may be traced through a chain of contacts such as the normal contacts of the inner-upper armature of relay 212, and thence through the normal contacts ofthe inner-upper armature of relay 218,*conductor 219, conductor 307, and iii we now assume the left hand group of relays oi the splitting circuit to be operated, through the lower armature and front contact of relay 308, conductor 309, conductor 00, winding of relay 101, armature and back contact of relay 102v to ground. lroviding the .various chain circuits above described are closed, which will indicate that 400, and at the saine time operates'relay .402. Relay 402 opens the original connection to ground, but since groundV is suppliedbyv the armature of relay 401, and since such *sub-Y stitute ground was connected to conductor 400 before relay 402 lbecome energized, there will be no break inthe continuity of this circuit.

It will be noted at this point that when at some later period, the circuit includingcon'- ductor 400 is opened and relay 401' becomes deenergized, that-during the period between.

the deenergization of the fast `relay 401 .and the slowing releasing relay 402, ground will i be disconnected from conductor 400 for al predetermined period oftiine. The purpose of thiswill be apparent hereinafter.

Upon the energization of relay 216it willv be noted that-through its lower armature, the continuity of the first chain circuit ydescribed is opened so that' no other trunk can advance to the .point of cooperation with the operators control and telephone circuit.

lAssuming that the operators telephone set snown at the right of F ig. l5 has been put in service, a circuit will .be established from ground, transformer winding 500, tip 501 of the telephone jack, tip 502 of the operators telephone plug, transmitter V508, tip 504 of relay 506,'conductor 5,08, conductor 405, conductor 813, middle lower armatureland front` 401 contact of relay 314'to ground (it has been assumed that the left hand group of splitting circuit relays are operated at this time) Vvlith the operation of relay 403, arcircuit is established for the Operationof" relay, 1406.

A circuit may now be traced from ground in Fig. 2, conductor 220, front contact and upper outer armature of relay 212, upper outer armature and front contact of relay v i216, conductor 221, conductor 810, conductor 811, conductor 312conductor 407 ,outer upper armature and front Contact of relay 406, to

the winding of relay 408, but since the other terminal of this relay is also connected to.

ground, this circuitis ine'ective. Another circuit may be traced from battery, winding of supervisory relay 222, conductor 223, armature 224 and its contact of relay 210,.cone ductor 225, conductor 815, conductor 316, coii ductor 817, conductor 409inner upper armature and front contact of relay 406, through the windingof relay 410 to ground'. lRelay 410 being of highresistance becomes ener-V gized in this circuit without causingthe enerygization of the supervisory relay 222. Upon the energization of relayf410, a circuit is esf tablished from ground, the normal contacts of the armatures of relay 509, conductor 510, V conductor 411, back contact and innerflower armature of relay 412, inner upper armature and back contact of relay 418, conductor 414, front contact and armature of relay410, c0nductoi' 415, Yconductor 511, normal contacts' of the middle upper -arniature'of relay i512,

conductor 518', winding of relay'514 to battery and ground. VUpon the energizat'ionof relay 514, a circuit is established. from battery, interrupter 515', winding' 516 of the order tone transformer 528', inner upper arma-r ture and front contact of relay 514, conductor 517, conductor 416, normal contacts of the i,....t. .]'1f-r lower ainiatuie of ie ay In, conductoi 418, vnormal contacts of the lower arinatureof re- '.llhe interrupted curK lay 419 to ground. rent flowingv through the'winding 516 will induce a tonecurrent in winding 518, which through the two outer upper armatures Vof relay 514 isrcoiinected through condenser 519 land the back contacts and two upper outer armatures of relay 520 to the tip and ring conductors 407 and 409, reached through the front contacts and upper armatures of relay 406. rlie path ot this tone current may be traced to conductors 220fand 223, whence by induction it will be transmitted over con-v ductors 200 and 201ftotheoutgoing end of. Athe trunk circuit. s f

Condenser 19 prevents a direct current path from being established from conductorv 220 toconductorr223 at this time whichif it were established would cause the operation ofA supervisory relay222/ A Vcircuit may now be traced from battery, winding of relay 417, conductor420, normal contacts of the lower armature of relayf520,

conductor 521, .front contact and inner lowery armature of relay 514 to ground..V Relay becomes energized in this circuit and opens the circuit'through the winding 516 and in.- terrupterfl so that the tone described is only transmitted back to the outoing end of the circuit during the interval from the energization of relay 514 to the energizatio-n of relay 417. Relay 417 beingslowto operate measures a predetermined period of ,tirne.'v

Upon thevenergization of'relay 41'? ground on conductor420 is connected throughthe front Y contact and `upper armature kof .relay 417, the winding of relay 421 to battery. Rey lay 421l slowly operates and at the end of the period measured thereby, it reconnects conductor 416 through the front contacts and i, lower armatures of relays 417 and'421 to cony ductor 418 so that lthe winding 516 again bef comes Veffective and a secondapplication of tone current is placed on the trunk conductors. Relay421 through its upper armature and front contact now causes the energize# tion of rela-y 419 and this relay becomes operated. Due to itsslow "operating character'` ica istics, it measures a similar interval of time as do relays 417 and 421. At the end of this period when the relay 419 has become operated, the circuit through winding 516 is again opened and the transmission of tone is again stopped,

' Relay 419 in operating now establishes a circuit from ground, front contact and lower armature or" relay 419, conductor 422, conductor 522, winding of relay 520 to battery and ground. Relay 520 opens the tip and ring conductors to the winding 518 and through the alternate contacts oi' its lower armature, places a ground directly on the winding ot relay 419 to maintain this relay operated after relays 417 and 421 have become deenergized. Relay 520 through its two upper outer armatures and front contacts connects the tip and ring conductors to the windings 529 and 530 of the operators set induction coil 531 and through the sleeves: 525 and 526 to the receiver 527. Thus the operators telephone set is now placed in talking condition since the order signal consisting in this case of two momentary applications of tone current has been transmitted to the. outgoing end of the trunk.

At the time when relays 204, 212 and 216 became energized, a circuit was established from battery, lower winding, front contact and lower armature of relay 204, front contact and middle armature of relay 212, innermost upper armature and front contact of relay 216, conductor 227, conductor 319, conductor 320, conductor 321, conductor 424, front contact and outermost lower armature oil? relay 403, inner upper armature and back contact of relay 425, conductor 426, concluetor 532, innermost lower armature and back contact of relay 524, conductor 533, conductor 427, winding of relay 428, conductor 429, conductor 534, lower armature and back contact of relay 512 to ground. Relay 428 is of such a resistance that it does not shunt the lower winding of relay 205 suliiciently to cause its deenergization. Relay 428 becomes operated and through its armature locks itself in this circuit independently of the ground supplied by the lower armature of relay 512.

When relay 520 operates as hereinbefore described, a circuit is established from battery, innermost upper armature and front contact of relay 520, winding of'relay 535 to ground. Relay 535 through its armature and front contact extends battery over conductor 536, winding of relay 512, normal contacts of the inner upper armature of relay 512, conductor 537, conductor 430 Through its lower original energizing circuit of relay 428. Through its middle upper armature relay 512 substitutes the ground supplied over conductor 430 and conductor 537, to the winding ot relay 514 in place of the ground supplied for the energization of relay 514 originally from the armature and contact of relay 410. Through its outermost upper armature and front contact, relay 512 causes the enerf gization of relay 509. Relay 509 opens the ground connection to the front Contact of relay 410.

At this time another circuit is established from ground, resistance 210, front contact and upper armature of relay 205, iront contact and outer upper armature of relay 204, armature 228 and its front contact of relay 216, conductor 229, winding of pilot relay 230, conductor 231, conductor 322, conductor 323, conductor 324, conductor 431, front contact and armature 432 of relay 403, con ductor 433, conductor 538, back contact and outer upper armature otrelay 539, conductor 540, conductor 434, back contact and outer upper armature of relay 413, conductor 441, inner upper armature and back contact of relay 435, winding of relay 436 to battery.

Relay 436 becomes energized iny this circuit and through its lower armature and front contact causes the energization of relay 437. Relay 437 in turn causes the energization of relay 438. Relay 438 through its front contact and inner armature places a direct battery connection on the winding of relay 436, and causes the shunting of both relay v436 and lamp208. ARelay 436 becoming shunted, releases its armature which in turn releases relay 437 and relay 438. lVhen relay 438 is returned to normal condition, the shunt will be removed from the winding of relay 436 and lamp 208, so that the lamp will again glow and relay 436 will again operate. This series of operations of relays 436, 437 and 438 will continue and cause the lamp 208 to flash periodically, and this condition will be maintained until the operator has communicated with the other operator at the outgoing end of the straightforward trunk of Fig. 2 and has pressed her release key 437 to cause the disconnection vof the operators control and telephone set from the straightforward trunk.

Since the further operations of these circuits have no particular bearing on thepres.- ent invention further detailed descriptions will not be given.

In a manner which will b e readily understood, without further detailed description, when a call is established over the call announcer trunk of Fig. l a circuit will be established from battery, winding of supervisory relay 105,*conductor 106,armature 107 of relay 103 and its front contact, conductor 108, conductor 226, conductor 318, upper out# er armature and back contact of relay'301,

conductor 311,'conductor 312, conductor 407,

the upper outer armature and front contact vof lrelay 406, and thence through the winding of relay 403- to ground. ARelay 403 like relay contacts of the armature of relay 509, conductor 510, conduct-or 411, back contact and inner lower armatureof relay 412, inner upper armature and back contact of relay 413, conrductor'414, armatureand frontk contact of relay 408, conductor 423, conduct0r-523, windf ing` of relay 524, to battery and ground. Re-

l upper armature of: relay y433 to the back conlay 524 becomes operated in this circuit.,

vUpon the operation of relay 524,.a circuit is established vfrom ground, front contact and outermost lower armature of relay 5,24, winding of relay 435itofbattery yand ground;v Relay 435 becomesoperated andjthrough its inner lower armature. and :front contact and through resistance 439 causes the 1 chain of vrelays 436, 437 and 433` to op-V crate. Through the inner upper armature of relay 435 both'windings of relay 440 are connected to conductor 441 which may be traced over theouter upper armature of relay 413 and its back contact, cond'uctor434, conductor v540, outer upper armature and back Contact of relay 539, conductor 538, conductor. 433, armature 432 and its front contact of relay 403, conductor 431,. conductor 324, conductor 323, ront contactand inner upper armature of relay 325, conductor 326,

conductor 232, conductor 109, winding of pilot relay 110, conductor 111, front contact and armature 112 ofrelay 103, conductor 113,l

to signal lamp 114 and thence to battery. i i

f of relay 119 to theline conductors-121 During the periods of energization of relay 433, ground will be connected from the outer tact of the lower armature of relay 442, to

the upper windingof relay 440 andithenwill cause the signal lamp 114 tofglow. .During the period of'"deenergization` of relay 438 this ground kconnection will be cut-cilandsignal lamp 11.4 will become dark. ...Relay 440 does not become energized under the'` present conditions. For further. detailed intormationas to the actionof this circuit,reference'is made to the application of William A. Rhodes,

Serial Number 203,051, filed June 2, 1927, Patent 1,757,217. i, Y f

Upon'the operation of relay'435 a circuit is established froml ground, back contact rand lower armature ofrelay 512, condu'ctor'429 'upper armature and front Contact of relay 435, winding of relay 443 to battery. Relay 443 establishes a'circuitffrom ground, 'inner upper armature andbaclrcontact of relay 442,tront contact: and armature of; relay 443,

, normal contacts'fot theflower armature of relay 444winding of relay 444, to'battery;

Relay.' 444 becomes energized in this circuit and locks in a ycircuit which may be traced over its front Contact and lower armature,

conductory445, conductor 541, front contact y and innermost lower armature of relay 524,.

conductor '532, conductor 426, back contact and inner upper armatureof relay 425, outermost lower armature land vfrontcontact of relay 403,conductor 424, conductor 321, conductor 320, back contact and outer upper armature ot relay 325, conductorf327, lconduc-y front contact and outer lower armature of l y relay A435, conductor 513, winding of relay 514 to battery andground. Relay 514 becoming energized Vconnects the winding 513 through the two outer upper armatures and front contacts of relay `514, over the back contacts and two outer upper armatures lof relay 520 to .the k tip kand ring conductors. Sincerelay 524 is energized at this time, the condenser l519 isv short-circuited, and the winding 518V actspasa direct current path acrossthe tip and ring conductors.y .'Under this 'condition supervisory relay 105 of the call announcer` trunk will be operated.

Thereupon a circuit will be established from ground, vthe front contact and lower armature of relay 118, the armature and fronticontact Aof relay 105, winding of relay 120 to battery.

Relay 120 reverses the connection of the windand122. Thisreversal act-sA as a signal to the outgong end of the `call announcer trunk.y

In thefmanner hereinbeore describedrelays417, 421 and 419 will become operated in sequence` finally causing the operation of relay '520 ywhereuponl the tip and ring con ductors are connected to the operators telephone circuit so that she'linay receive the number pronounced by the apparatusat the` distant end of the call announcer trunk. The fact that two applications of tone'are made to this trunk is immaterial since no operatorlis atthe'other endvto listen. The'conf ne'c'tion of coilV 518 to thevtip and ring contion of relay 514 tothe operation of relay 520 orms an order signal in theform of an apf'plic'ationoi direct current.

No further detailed description of these circuits is belieyedvto 'be necessary at ythe present time since vthe furtheroperatlons arek not :concerned Ywithfthe present,invention.v lngeneral whenthe number requiredy overY the`V` callv announcer trunk-y hasjbeen,l productorsfduring the interval romgthe operanounced, the operator at this point will press the release key 439 which will result in the disconnection of her control and telephone circuit through the trunk of Fig. 1.

In accordance with another form or" the i'nvention illustrated by the drawings as arranged in Fig. 11, a call coming in over the straightforward trunk of Fig. 2 will be extended through the sequence circuit of Fig. 2 and the splitting circuit of Fig. 3 in the same manner as hereinbefore described and thence to the operators control and telephone circuit of Figs. 8 and 9. Conductor 800 and relays 801 and 802 correspond exactly to conducto'r 400 and relays 401 and 402, so that relay 216 will be energized in the manner hereinbefore described.

l/Vhen the operators telephone set is plugged into its jack in Fig. 9, a connection will be established from ground,y winding 900 or the operators telephone set induction coil 931, the tip 901 or the operators telephone jack, tip of plugl 902, transmitter 903, tip of plug 904, tip 905 of the operators telephone set jack, winding of relay 906 to battery. Upon the operation or relay 906, a connection is established from battery, winding of relay 803, conductor 804, conductor 907, armature and front contact of relay 906, conductor 908, conductor 805, conductor 313, middle lower armature and front contact of relay 314 to ground. Relay 803 becomes operated in this circuit and causes the operation of relay 806.

rIhe tip and ring conductors 220 and 223 are now extended through the upper arma'- tures and` front contacts of relay 806 `to conductors .7 and 808 respectively. Thus the ground of conductor 220 will be connected over conductor 807 to the winding of relay 809 and thence to battery and ground. Relay 809 becomes energized in this circuit.A At the same time battery on conductor 223 will be connected over conductor 808 to the Winding or relay 810 and thence to ground. Relay 810 is of high resistance and becomes energized in this circuit withoutl causing the energization of the supervisory relay 222. It should be especially noted that when n the straightforward trunk of Fig. 2 in which neither the tip nor ring conductors 221 or 225 is blocked by a condenser is extended to the operato-rs control and telephone circuit, the-n both relays 809 and 810 will respond.

A circuitis now established from ground, normal contacts of the armature of relay 909, conductor 910, conductor 811, the back contact and inner lower armature of relay 812, the inner upper armature and back Contact or relay 813, conductor' 814, armature and front contact or relay 810, winding of relay 815 to battery and ground. Relay 815 becoming energized establishes a circuit from ground, front Contact and outer lower arma-l ture or' relay 815, armature and front con# iframe 13 tact or relay 809, inner lower armature and fro-'nt Contact or relay 815, conductor 816, conductor 911, normal contacts or the mid-` dle upper armature ofrelay 912, conductor 913, winding of relay 914 to battery. Relay 914 responds in this circuit and through its two outer upper armatures and front contacts connects the secondary winding 915 or" the order tone transformer 916, through condenser 917 and the back contacts and two outer upper armatures of relay 918 to tip and ring conductors V807 and 808. A circuit -for the primary winding 919 of the transformer 916 is now established from battery, interrupter 817, normal contacts or the lower armature or relay 818,back contact and inner lower armaturevof relay 819, conductor 820, conductor 920, front contact and inner upper armature of relay 914, winding 919, conducto'r 921, conductor 821, normal contacts or the lower armature of relay 822 to ground. Through induction the tone generated by the circuit including interrupter 817 is transmitted thro-ugh the secondary winding 915 to the outgoing end of the trunk circuit.

Relay 914 alsov establishes a circuit from ground, the inner lower armature and front contact or relay 914, conductor 922, back contact and lower armature of relay 918, windin of relay818, to battery. Relay 818 after a predetermined interval moves its armatures into their operated position whereupon the circuit t'or the primary coil 919 is opened and the transmission of tone is stopped.

At the same time relay 818 establishes a circuit `from its front contact and upper armature through the outer lower armature and back Contact or relay V819, winding of relay 823 to battery. Relay 823 after a predetermined interval moves its armatures into their operating position, whereupon the circuit for the primary winding 919 is conipleted from the interrupter 817, through the front contact and lower armature or relay 823 and the lower armature and front Contact or relay 818 over the circuit hereinbefor-e described. Relay 823 establishes a circuit for the energization of reiay 822, and this relay after a predetermined interval or time moves its armatures into theirfoperated position, whereupon the circuitfor the primary coil 9,19 is opened at the lower armature oi" relay 822.

At the same time relay 822 establishes a circuit romground, front contact and lower armature of relay 822, conductor 824, conductor924, winding of `relay 918 to battery. Relay 918 disconnects the tip andring conductors from the primary coil 915 and transfers them to the operators telephone set, overconductors 925 and 926.

In the same manner as hereinbefore described, a circuit is established Jfrom'battery, lower winding of relay 204, front contact and lower armature relay 204, tront- Contact Ezi0 and middle armature oiirelay 212, innermost armature and front Contact of relay 216,'conductor 227, conductor 319-, conductor 320,/con- ,ductor321, conductor825, front contact and the lowermost e-rinature ofrelay 803, inner upper armature and back contact ofrelayv 826, conductor 827, conductor 923, innermost lower arniaturefand back contact of relay 927, conductor 928, conductor 828, winding of relay 829, conductor 830, conductor 929, lower armature and bacl Contact of relay 12 to ground. Relay 829 again operates in this circuit and by its armature vsubstitutes a local ground for that supplied overthe lower armature oif'relay 912. o I

Relay 829 also places ground on. conductor 830 whereby a circuit' isestablished from battery, innermost upper armature and fron contact of relay 918, lower armature and Jfront contact of relay 930, winding'of relay 912, back contact and innermost upper arma-V ture of relay 912, conductor 932, conductor 830over the contacts and armature of relay 829 to ground. Relay912 responds and locks over the lalternate contacts of its innermost upper armature.4 This relay also opens the original ground for theenergization.oiE relay 829.Y Through its outermost upper armature,

and upper armature of relay 205, front conf.

tact and outer upper larmatureof relayv 204, armature 228, and its front contact of lrelay 216, lconductor 229, winding of pilot relay 230, conductor 231, conductor 322, conductor 323, conductor 324,conductor v831, iront contact and armature 832 oit' relay 803, conductor 834," conductor 932, back Contact and outer upper armature of relay 983, conductor 934,

1' conductor835, back Contact and outer upper armature 01:' relayv 813, conductor 836, inner upper armature and back Contact of rrelay,

83?, winding of relay 838 to battery.

.Relay 838 becomes .energized andloauses the' energization in turn oi relay 839 and this relay in turncauses the energization of relay 840 which now shunts rrelay838 and lamp 208 in amanner hereinbefore.described. v1Whencrelay 838 is sliunted it releases its armatures which in turn releases relays 839 and 840.` '1" hereupon this cyclev ot operation reoccurs, and as a consequence lamp 208 -will continue to flash until. the operator depresses'- lier release lrey 841.v Further operation .of

the straightforward trunk of Fig. 2.a`i'idtheV opr-irators control and telephone circuit will .not be described since .they have no particular connection with the present invention. The tandem straightforward trunk shown in Fig. 6 is in all essentialwdetails the same as the vstraightforward :trunkvv shown in Fig.' r2.- Sincethis trunk is used for tandem work,

however, it is `nowfne'eessa'ryto givethe outf going operatory a different kind ot order signal. ATherefore a condenser 600 is placed' in the ring conductor 601 so as to prevent the `operation ot relay 810 in the operators control circuit.

Therefore when a tandem straightforward trunk is connected through its sequence circuit and the splittingcircuit ofFig. .3;to the opera'tors circuit of Figs. 8

vand 9only relay 809 willrespond. -f A circuit is now established from ground,

the normal contacts of the armature of relay 909, conductor 910, conductor 811, back con@V ftac't and inner lower armature of relay 812, inner upper armature and back., contact of-l relay'818, conductor` 814, armature and back Contact of relay 810, armature and front contact of relay 809, inner lower armature .and `back contactv of relay 815windiiig oit relay 819vto batte ry. lelay 819 placesa ground von conductor 816 which may be further traced over conductor 911,- thencriiial'con` tacts of the middle .upper armature of relay 912, Conductor 913, winding'of relay'914, to

battery and ground. Relay 914 VConnects the secondary winding 915 of the tone transformer 916 through the u 3 er outer armature of relay 914 andcondenser 917.and theback contacts and two upper outer armatures of relay 918 `of the'tip and ring conductors-807 andeoaf- VVAi s A circuit for the primary coil 919'is now yestablished from battery, low tone inter-- rupter 8.42, the hack contactand armature'of relay-843,'. conductor 844, the front Contact and inner lowerarmature or relay 819, con

`ductor 820, conductor 920,1lront Contact vand inner upper armature oit' relay 914, winding 919 .of transformer 916, conductor 921, con-A ductor ,821, normal kcontacts of the lower armature of relay 822 to ground. Throughthis circuit a low tone is transmitted to the out going end of the Atandem, straightforwardv Upon the operationo'f relay 914e circuit V established from ground, inner lower "armature and rontcontact of relay9-14, conductor 922, baclr Contactl and lowerarmaturejof re? lay 918, to the winding o-relay 818 and thence toy battery. Relay 818 becomes energized in this circuit after a predetermined interval of time. Thereuponfa v'circuitis establishedv from ground, front Contact and upper armature of relay 818, outer lower armature and front contact of relay 819,,conductor 845,

winding of relay 846 to battery and ground.

Relay 846 slowly attracts its armaturesand after' a predeterminedyinteryal 0 1' tinieeS--r I tablishes a circuit from ground, back contactfand lright hand armature of relay 847,

- f lett hand armature and front Contact` ofre- .lay 846, winding of relay 843 to batteryand ground. Relay 843 transfers ,conductor-.1844

' from connection tothe low tone interrupter 842 to co-nnection to the high tone interrupter 848 whereupon the pitch of the tone being transmitted to the outgoing end of the tandem straightforward trunk is changed.

The operation of relay 846 also results in the establishment of a circuit from battery and ground, front contactVV and right hand armature of relay 846, winding of relay 847 to battery. `After a predetermined interval of time, relay 847 attracts its armatures and by opening the circuit of relay 843 again changes the pitch of the tone being trans mitted to the outgoing end of the trunlr circuit o F ig. 6 to a low tone. Relay 847 also connects ground through its right hand arma-v -ture and front Contact to conductor 849,

which extends to the winding of relay 823 and thence to battery. ARelay 823 now becomes operated' and causes the operation of relay '822 which after an interval opens the circuit of the primary winding 919 to stop the transmission of tone. This signal just described consists of irst a low tone, then a hih tone and again a low tone and may be termed a bugie tone, which is different and may be readily distinguished from the two momentary applications of tone applied to the straightforward trunk of Fig. 2.

The other operations of the circuit such as 'the operation ofthe chain of relays 838, 839 and 840 which causes the flashing of the signal lamp 602 are the same as liereinbetore described in connection with the straightforward trunk of F ig. 2.

lf a call comes in overthe call announcer trunk of Fig. 7 Vthen due to the fact that a condenser 700 is placed in the tip conductor 701, relay 809 will fail to operate and relay 810 will become operated. Under these conditions a circuit isrestablished from ground, normal conta-cts of the armature oi'l relay 909, conductor 910, conductor 811,r back Contact and inner lower armature of relay Y812, inner upper armature and back contact ot relay 813, conductor 814, armature and front contact of relay 810, winding of relay 815 to battery and ground. Relay 815 establishes a circuit from ground, front contact and outer lower 'armature of relay 815, armature and back contact of relay 809, upper armature and front contact ot relay 815, winding of relay 850, to battery and ground: Relay 850 be:- coming operated establishes a circuitrfrom ground, innermost upper armature and iront contact of relay 850, conductor 851, conductor 935, winding ofrelay 927 to battery. Relay 927 becoming operated causes the operation of relay 837 whereupon the relays838, 839 and 840 are started into operation through the movement of the inner lower armature of relay 837 and the signal lamp 702 is caused to flash in the manner hereinbeiore described.

Upon the operation of relay 850 Va circuit is established trombattery through winding` 703 of the supervisory relay of the call announcer trunk of Fig. 7 over the ring conductor 704, armature 705 and its front contact of relay 706, conductor 707, conductor 234, conductor 328, inner upper armature and back contact of relay 301, conductor 316, conductor 317, inner upper armature and front contact of relay 806, conductor 808, resist-ance 852, front contact and outermost upper armature of relay 850, normal contacts of the lower armature of relay 822 to' gro-und. This causes the energization of supe-rvisory relay 703 whereupon a circuit is established from ground, front contact and lower armature of relay 708, conducto-r 709, armature and contact of supervisory relay V703, winding of relay 710 to battery which upon operating reverses the current flow in conductors 711 and in 712.

Upon the operation of relay 837 hereinbefore described, a circuit is established from ground, back contact and lower armature of relay 912, conductor 929, conductor 830, outer upper armature and front contact of relay 837, winding of relay 853L to battery. Relay 853 in operating establishes a connection from ground, inner upper armature andback contact of relay 854, front contact and armature'of relay 853, normal contacts of the lower armature or relay 855to battery. Relay 855 locks over conductor 856 through conductor 936, the front contact and innermost lower armature of relay 927, conductor 923, con'- ductor 827, bac-k contact and inner upper armature oi relay 826, outermost lower arma,- ture and front contact of relay 803, conductor 825, conductor 321, conductor 320, back contact and outer upper armature of relay 325, conductor 327, conductor 233, conductor 713, front contact and innermost upper armature of relay 706, middle armature and front contact of relay 714, lower winding'ot relay 715, lower winding of relay 708, to ground supplied over the armature of relay 716. Relay 855 through its operation places ground on conductor 830 which is now extended over the front contact and outer lower armature of relay 837, vconductor 937, conductor 922, backvcontact and lower armature of relay 918, winding of relay 818 to battery and ground. Relay 818 becoming energized causes in turn the energization of relay 823 and this in turn causes the energization of relay 822. l/Vhen relay 822 becomes operated it cuts oil the ground for causing the energization of t-he supervisory relay 703, and by placing a ground lon conductor'824 causes the energization of relay 918. Relay 918 connects the tip and ring conductors 807 and 808 to the operators telephone circuit so that when in response to the reversal of the current ilow in the conductors 711 and 712 the apparatus of the call announcer trunk pronounces the number of the wanted line, the operator here will receive the' message.

Since further operations in connection With the extension of the call announcer' trunkhave no particular bearing on the present application, no further detailed description will be given.

Vhat is claimed is:

l. In a telephone system, an operators control circuit, means in said control circuit for transmitting a plurality of different order signals, and means for selectively operating said last means.

2. In a telephone system, trunks of dierent character, an operators control circuit, means in said control circuit for transmitting a plurality of different order. signals, and means responsive to the connection of one of said trunks to said control circuit for selectively operating said last means in accordance With the character of the said trunk.

3. In a telephone system, an operators position, an operators control circuit thereat, groups of trunks, means responsive to the seizure of one of said trunks for connecting said control circuit to said seized trunk, means effective incident to the connection of said control circuit to said trunk for transmitting an order signal over said trunk, means in said control circuit for distinguishing between said groups of trunks and means responsive thereto for changing the character of the said order signal.

4. In a telephone system, an operators p osition, an operators control circuit thereat, groups of trunks terminating in said position, means responsive to the seizure of one of said trunks for connecting said control circuit to said seized trunk, means effective incident to the connection of said control circuit to said trunk for transmitting an order signal over said trunk, means in said control circuit for distinguishing loetvveen said groups of trunks and means responsive thereto for changing the character of the said order signal. l

5. In a telephone system, groups of trunks, an operators control circuit, a circuit individual to each said group of trunks for connecting the trunks of a said group in sequence to said control circuit, means in said control circuit effective incident to the connection of one of said trunks to said control circuit to transmit an order signal oversaid connected trunk, means in said sequence circuits for characterizing the trunks of the corresponding groups, and means in the ysaid control circuit responsive thereto for changing the character of the said order signal.

6. In a telephone system, groups of trunks, an operators control circuit, a circuit individual to each said group of trunks for connecting the trunks of a said group in sequence to said control circuit, means in said control circuit effective incident to the connection of one of said trunks to said control circuit to transmit an order signal over said connected trunk, a pair of relays in said control circuit operable in different 'combinations for correspondingly changing the character of the said order signal, and means for altering the different sequence circuitsto cause said relays to operate in diiferent combinations.

7. In a telephone system, groups of trunks, an operators control circuit, including a. tip and a ring conductor, a circuit including a tip and a ring conductor individual to each said group of trunks for connecting the trunks of a said group in sequence to said control circuit, means in said control circuit effective incident to the connection of one of said trunks to said control circuit to transmit an order signal over said connected trunk,

a relay connected to the tip conductor and a relay connected to the ring conductor of said control circuit operable in different combinations for correspondingly changing the character ci the said order signal, and condensers connected in series With said tip and ring conductors of said sequence circuits in diiterent combinations to control the operation of said relays.

In Witness whereof, I hereunto subscribe my name, this 5th day of August, 1929.

WILEY WHITNEY. 

